Oh so this is why my bilge is always wet!

Sep 24, 2018
3,392
Catalina 30 MKIII Chicago
There's two plastic through hulls for the cockpit drain. One that goes through the transom and the other that's in the cockpit. I discovered a crack in the cockpit one. Does anyone know what size it is? I can see O'Day cut the nipple in it at a 45 because it's such a tight fit. Nothing is listed on D&R. I guess it's too generic of a part
 

SFS

.
Aug 18, 2015
2,085
Currently Boatless Okinawa
I think this is a pretty common problem. One of my two cockpit drains cracked at the threads, and would no longer tighten down. I took everything out and evaluated the hole diameter, floor thickness, elbow angles (90 vs 60 degrees), and connection options. Then I went to the big box store and designed my own fix. The hardest part to find was one that was as close to flush with the cockpit floor as possible, so that the water level didn't have to rise to 1/4" before any draining started.

This method was cheaper than West Marine, and offered me many more options. I would provide more detail, but it's been so long, and I've slept since then.
 
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capta

.
Jun 4, 2009
4,926
Pearson 530 Admiralty Bay, Bequia SVG
If you are going to replace a thruhull, I'd suggest putting in a bronze one, and that problem will not reoccur.
 
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Sep 24, 2018
3,392
Catalina 30 MKIII Chicago
I think this is a pretty common problem. One of my two cockpit drains cracked at the threads, and would no longer tighten down. I took everything out and evaluated the hole diameter, floor thickness, elbow angles (90 vs 60 degrees), and connection options. Then I went to the big box store and designed my own fix. The hardest part to find was one that was as close to flush with the cockpit floor as possible, so that the water level didn't have to rise to 1/4" before any draining started.

This method was cheaper than West Marine, and offered me many more options. I would provide more detail, but it's been so long, and I've slept since then.
What did you use for the flange? On my boat, the water must rise about an inch. There's a pocket or well in back of the cockpit which has a flange mounted perpendicular to the cockpit sole. Terrible design. Oday later revised the design.
If you are going to replace a thruhull, I'd suggest putting in a bronze one, and that problem will not reoccur.
The current one lasted 45 years and I've been looking for a new boat
 

SFS

.
Aug 18, 2015
2,085
Currently Boatless Okinawa
I don't remember what I used for the flange, I'm really sorry. It's been 7 years (how is that possible?), and I just don't recall.
 
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Sep 24, 2018
3,392
Catalina 30 MKIII Chicago
I wonder if my bilge qualifies as a superfund site. It's pretty nasty due to the fact that it's always wet
 
Mar 2, 2019
590
Oday 25 Milwaukee
Mayhem , I beleive your 25 is a '79 correct ? Our's is a'81 . We have the cockpit drain in the rear that flows out the transom and below the rudder grudgeons. At the front of the cockpit there is only the line a for the centerboard . I also have been chasing a persistant leak in the bilge for almost 20 years . Any chance for a picture ?
 
Sep 24, 2018
3,392
Catalina 30 MKIII Chicago
Mayhem , I beleive your 25 is a '79 correct ? Our's is a'81 . We have the cockpit drain in the rear that flows out the transom and below the rudder grudgeons. At the front of the cockpit there is only the line a for the centerboard . I also have been chasing a persistant leak in the bilge for almost 20 years . Any chance for a picture ?
Close, Mine is a 78. I measured an ID of 1.45" with the caliper at a slight angle. I'll have to look up specs of the through hull I installed on the transom for the the thread size. I remember that I was not able to find an exact match.

My lower gudgeon is below the through hull. Not a good configuration. I had to replace the lower gudgeon after a storm tore up the 1/4" stainless. I had a dribble of water squeeze out of the transom as I tightened the bolts! There was also zero sealant on the original install.

I'll grab a pic for you the next time I go for a sail
 
Sep 24, 2018
3,392
Catalina 30 MKIII Chicago
Mayhem , I beleive your 25 is a '79 correct ? Our's is a'81 . We have the cockpit drain in the rear that flows out the transom and below the rudder grudgeons. At the front of the cockpit there is only the line a for the centerboard . I also have been chasing a persistant leak in the bilge for almost 20 years . Any chance for a picture ?
Also check for screw holes in the bottom of your bilge. Our keels probably aren't well sealed and if there's a hole that goes between the bilge and keel then of course there's potential for water